Electron-Electron Correlation Effects in Low-Dimensional Conductors and Superconductors

Electron-Electron Correlation Effects in Low-Dimensional Conductors and Superconductors PDF Author: Alexandr A. Ovchinnikov
Publisher: Springer Science & Business Media
ISBN: 3642767532
Category : Science
Languages : en
Pages : 170

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Book Description
Advances in the physics and chemistry of low-dimensional systems have been really magnificent in the last few decades. Hundreds of quasi-one-dimensional and quasi-two-dimensional systems have been synthesized and studied. The most popular representatives of quasi-one-dimensional materials are polyacethylenes CH [1] and conducting donor-acceptor molecular crystals TIF z TCNQ. Examples of quasi-two-dimensional systems are high temperature su perconductors (HTSC) based on copper oxides LA2CU04, YBa2Cu306+y and organic superconductors based on BEDT -TIP molecules. The properties of such one- and two-dimensional materials are not yet fully understood. On the one hand, the equations of motion of one-dimensional sys tems are rather simple, which facilitates rigorous solutions of model problems. On the other hand, manifestations of various interactions in one-dimensional systems are rather peculiar. This refers, in particular, to electron--electron and electron-phonon interactions. Even within the limit of a weak coupling con stant electron--electron correlations produce an energy gap in the spectrum of one-dimensional metals implying a Mott transition from metal to semiconductor state. In all these cases perturbation theory is inapplicable. Which is one of the main difficulties on the way towards a comprehensive theory of quasi-one-dimensional systems. - This meeting held at the Institute for Theoretical Physics in Kiev May 15-18 1990 was devoted to related problems. The papers selected for this volume are grouped into three sections.

Electron-Electron Correlation Effects in Low-Dimensional Conductors and Superconductors

Electron-Electron Correlation Effects in Low-Dimensional Conductors and Superconductors PDF Author: Alexandr A. Ovchinnikov
Publisher: Springer Science & Business Media
ISBN: 3642767532
Category : Science
Languages : en
Pages : 170

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Book Description
Advances in the physics and chemistry of low-dimensional systems have been really magnificent in the last few decades. Hundreds of quasi-one-dimensional and quasi-two-dimensional systems have been synthesized and studied. The most popular representatives of quasi-one-dimensional materials are polyacethylenes CH [1] and conducting donor-acceptor molecular crystals TIF z TCNQ. Examples of quasi-two-dimensional systems are high temperature su perconductors (HTSC) based on copper oxides LA2CU04, YBa2Cu306+y and organic superconductors based on BEDT -TIP molecules. The properties of such one- and two-dimensional materials are not yet fully understood. On the one hand, the equations of motion of one-dimensional sys tems are rather simple, which facilitates rigorous solutions of model problems. On the other hand, manifestations of various interactions in one-dimensional systems are rather peculiar. This refers, in particular, to electron--electron and electron-phonon interactions. Even within the limit of a weak coupling con stant electron--electron correlations produce an energy gap in the spectrum of one-dimensional metals implying a Mott transition from metal to semiconductor state. In all these cases perturbation theory is inapplicable. Which is one of the main difficulties on the way towards a comprehensive theory of quasi-one-dimensional systems. - This meeting held at the Institute for Theoretical Physics in Kiev May 15-18 1990 was devoted to related problems. The papers selected for this volume are grouped into three sections.

Correlation Effects in Low-Dimensional Electron Systems

Correlation Effects in Low-Dimensional Electron Systems PDF Author: Ayao Okiji
Publisher: Springer Science & Business Media
ISBN: 3642851290
Category : Science
Languages : en
Pages : 223

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Book Description
Correlation Effects in Low-Dimensional Electron Systems describes recent developments in theoretical condensed-matter physics, emphasizing exact solutions in one dimension including conformal-field theoretical approaches, the application of quantum groups, and numerical diagonalization techniques. Various key properties are presented for two-dimensional, highly correlated electron systems.

Low-Dimensional Systems

Low-Dimensional Systems PDF Author: Tobias Brandes
Publisher: Springer
ISBN: 3540464387
Category : Science
Languages : en
Pages : 220

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Book Description
Experimental progress over the past few years has made it possible to test a n- ber of fundamental physical concepts related to the motion of electrons in low dimensions. The production and experimental control of novel structures with typical sizes in the sub-micrometer regime has now become possible. In parti- lar, semiconductors are widely used in order to con?ne the motion of electrons in two-dimensional heterostructures. The quantum Hall e?ect was one of the ?rst highlights of the new physics that is revealed by this con?nement. In a further step of the technological development in semiconductor-heterostructures, other arti?cial devices such as quasi one-dimensional ‘quantum wires’ and ‘quantum dots’ (arti?cial atoms) have also been produced. These structures again di?er very markedly from three- and two-dimensional systems, especially in relation to the transport of electrons and the interaction with light. Although the technol- ical advances and the experimental skills connected with these new structures are progressing extremely fast, our theoretical understanding of the physical e?ects (such as the quantum Hall e?ect) is still at a very rudimentary level. In low-dimensional structures, the interaction of electrons with one another and with other degrees of freedoms such as lattice vibrations or light gives rise to new phenomena that are very di?erent from those familiar in the bulk ma- rial. The theoretical formulation of the electronic transport properties of small devices may be considered well-established, provided interaction processes are neglected.

Low-Dimensional Conductors and Superconductors

Low-Dimensional Conductors and Superconductors PDF Author: D. Jerome
Publisher: Springer Science & Business Media
ISBN: 1489936114
Category : Technology & Engineering
Languages : en
Pages : 524

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Book Description
Research activities in low dimensional conductors have shown a rapid growth since 1972 and have led to the discovery of new and remarkable phy sical properties unique to both molecular and inorganic conductors exhibi ting one-dimensional transport behaviour. This NATO Institute was a conti nuation of aseries of NATO Advanced Study Institutes of Worshops which took place at regular intervals till 1979. This is the first time, however, that charge density wave transport and electronic properties of low dimen sional organic conductors are treated on an equal footing. The program of the Institute was framed by tutorial lectures in the theories and experiments of low dimensional conductors. The bulk of the course covered two series of low-dimensional mate rials with their respective properties. 1) The I-D inorganic conductors exhibiting the phenomena of sliding charge density waves, narrow band noise, memory effects, etc ..• 2) Low-dimensional crystallized organic conductors giving rise to various possibilities of ground states, spin-Peierls, spin density wave, Peierls, superconductivity and magnetic-field induced spin density wave, etc ... Since it has been established from the beginning that this Institute was to be devoted essentially to the Physics of Low Dimensional Conductors, only one main course summarized the progress in chemistry and material preparation.

Physics and Chemistry of Low-Dimensional Inorganic Conductors

Physics and Chemistry of Low-Dimensional Inorganic Conductors PDF Author: C. Schlenker
Publisher: Springer Science & Business Media
ISBN: 1461311497
Category : Science
Languages : en
Pages : 477

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Book Description
The field of low-dimensional conductors has been very active for more than twenty years. It has grown continuously and both the inorganic and organic materials have remark able properties, such as charge and spin density waves and superconductivity. The discovery of superconductivity at high temperature in copper-based quasi two-dimensional conducting oxides nearly ten years ago has further enlarged the field and stimulated new research on inorganic conductors. It was obviously impossible to cover such a broad field in a ten day Institute and it seemed pertinent to concentrate on inorganic conductors, excluding the high Tc superconducting oxides. In this context, it was highly desirable to include both physics and chemistry in the same Institute in order to tighten or in some cases to establish links between physicists and chemists. This Advanced Study Institute is the continuation of a series of similar ones which have taken place every few years since 1974. 73 participants coming from 13 countries have taken part in this School at the beautiful site of the Centre de Physique des Houches in the Mont-Blanc mountain range. The scientific programme included more than forty lectures and seminars, two poster sessions and ten short talks. Several discussion sessions were organized for the evenings, one on New Materials, one on New Topics and one on the special problem of the Fermi and Luttinger liquids. The scientific activity was kept high from the beginning to the end of the Institute.

Electron-Electron Interactions in Disordered Systems

Electron-Electron Interactions in Disordered Systems PDF Author: A.L. Efros
Publisher: Elsevier
ISBN: 044460099X
Category : Science
Languages : en
Pages : 703

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Book Description
``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

Electron Correlations in Molecules and Solids

Electron Correlations in Molecules and Solids PDF Author: Peter Fulde
Publisher: Springer Science & Business Media
ISBN: 3642578098
Category : Science
Languages : en
Pages : 492

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Book Description
Dieser Titel verbindet die Festkörpertheorie mit der Quantenchemie. Neue Konzepte der Vielteilchen-Verarbeitung und Korrelations-Effekte, normale quantenchemische Verfahren mit Projektionstechniken, Greensche Funktionen und Monte-Carlo-Methoden werden erarbeitet. Anwendungsbereiche der Molekültheorie, von Halbleitern, supraleitender high-Tc-Materialien, etc., werden vorgestellt.

Physics of Transition Metal Oxides

Physics of Transition Metal Oxides PDF Author: Sadamichi Maekawa
Publisher: Springer Science & Business Media
ISBN: 3662092980
Category : Technology & Engineering
Languages : en
Pages : 345

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Book Description
The fact that magnetite (Fe304) was already known in the Greek era as a peculiar mineral is indicative of the long history of transition metal oxides as useful materials. The discovery of high-temperature superconductivity in 1986 has renewed interest in transition metal oxides. High-temperature su perconductors are all cuprates. Why is it? To answer to this question, we must understand the electronic states in the cuprates. Transition metal oxides are also familiar as magnets. They might be found stuck on the door of your kitchen refrigerator. Magnetic materials are valuable not only as magnets but as electronics materials. Manganites have received special attention recently because of their extremely large magnetoresistance, an effect so large that it is called colossal magnetoresistance (CMR). What is the difference between high-temperature superconducting cuprates and CMR manganites? Elements with incomplete d shells in the periodic table are called tran sition elements. Among them, the following eight elements with the atomic numbers from 22 to 29, i. e. , Ti, V, Cr, Mn, Fe, Co, Ni and Cu are the most im portant. These elements make compounds with oxygen and present a variety of properties. High-temperature superconductivity and CMR are examples. Most of the textbooks on magnetism discuss the magnetic properties of transition metal oxides. However, when one studies magnetism using tradi tional textbooks, one finds that the transport properties are not introduced in the initial stages.

Superlattices and Other Heterostructures

Superlattices and Other Heterostructures PDF Author: Eougenious L. Ivchenko
Publisher: Springer Science & Business Media
ISBN: 3642606504
Category : Technology & Engineering
Languages : en
Pages : 396

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Book Description
Superlattices and Other Heterostructures deals with optical properties of superlattices and quantum-well structures with emphasis on phenomena governed by crystal symmetries. After a brief introduction to group theory and symmetries, methods to calculate spectra of electrons, excitions and phonons in heterostructures are discussed. Further chapters cover absorption and reflection of light under interband transitions, cyclotron and electron spin-resoncance, light scattering by free and bound carriers as well as by optical and acoustic phonons, polarized photoluminescence, optical spin orientation of electrons and excitions, and nonlinear optical and photogalvanic effects.

Relaxations of Excited States and Photo-Induced Phase Transitions

Relaxations of Excited States and Photo-Induced Phase Transitions PDF Author: Keiichiro Nasu
Publisher: Springer Science & Business Media
ISBN: 3642607020
Category : Science
Languages : en
Pages : 279

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Book Description
Message from The Taniguchi Foundation Dr. Kanamori, Distinguished Guests and Friends: The Taniguchi Foundation wishes to welcome the participants of the nine teenth International Symposium on the Theory of Condensed Matter, who have come from within this country and from different parts of the world. The concept of the symposium is unique in that participants, both Japanese and from abroad, are limited in number to small discussion groups, and live together, although for a short period, as a close-knit community. We feel that this kind of environment will assist towards the strengthening of understanding and the fostering of friendship among the attendees. It is easy to talk about, but difficult to realize, the ideal of international friendship and understanding in a world which is steadily growing smaller. So far, the Foundation has invited a total of 149 participants in this division from 24 foreign countries and 299 participants from Japan. And we are all friends. We hope and trust that even after they have reached the heights of academic fame during the coming decades, the participants will continue to join forces and help to forge closer bonds of friendship and cooperation that will make major contributions not only to academia, but also towards world peace and the welfare of mankind. We hope that all the participants will return home with warm memories of both this symposium and the pleasant times that we have shared. Thank you.